Argument:

A discussion on a point, topic or theme following the structure Premise + premise -> conclusion

Conclusion:

A statement in an argument that asserts something, says that something is true.  In an argument a conclusion  is supported by other statements, called premises.

Premise:

A premise is a statement in an argument that supports a particular conclusion.

Assumption:

Something not stated that must be true in order for a premise or a conclusion to be true.  Meanings are a kind of assumption: every word in a statement has a meaning or set of meanings that could be stated in order to make the statement more clear.

In an argument people can actually agree on a premise or conclusion while agreeing to quite different things, if they have different assumptions about what words in the statement mean, or different assumptions about the things referenced in the statement.

Hidden Assumption:

A hidden assumption is one that has not been considered or uncovered.

Statement:

Any assertion whatsoever, including conclusions, premises, supporting premises, and sentences related in no way to an argument at hand.

Supporting Premise:

A premise that supports another premise in the same way that a premise might support a conclusion.  A supporting premise has another premise as its conclusion.   (A supporting premise may also be a premise that supports the ‘proper’ conclusion.)

Dialectic:

Thesis + antithesis -> synthesis

A mode or method of debate.  The dialectic is sometimes called the ‘Socratic method’.  It is used for discovering different sides of an argument and comparing their strengths.  For this reason it is considered a philosophical rather than a rhetorical tool.  That is, the dialectic is often thought to be about discovering what is true rather than persuading others to believe a particular argument.

The dialectic consists of an idea, an assertion, a proposition (a statement or conclusion) called a ‘thesis’.  The method of the dialectic requires that the opposite of the thesis also be found: the ‘anti-thesis.’

When the thesis and the antithesis are brought together and assumptions about them examined, it is possible to develop a ‘synthesis’:  determining which is the most reasonable of thesis/antithesis.

Dichotomy

A dichotomy is a pair of binary opposites.  Examples of dichotomies are 0/1, right/wrong, up/down, left/right.   An argument is dichotomous when two opposing assertions are presented.  For example the argument ‘It’s good to be rich’ has the opposing assertion ‘It’s wrong to be rich.’  An argument like ‘either you’re with us or you’re against us’ is also based on a dichotomy: on opposing ideas.

Any debate topic is a dichotomy, since it is presented in a form in which speakers are ‘for’ and ‘against’ a proposition.

False Dichotomy

The presentation of two opposing positions as the only two choices, where in fact there are others.

e.g Either you’re with us or you’re against us.

The example is a clear case of false dichotomy. The argument presents two choices, when in fact there are clearly more options. The audience might feel neutral towards the speaker but is not given that choice.

Many dichotomous arguments can be shown to be false by drawing the dichotomy out into a ‘continuum’.  If a dichotomy is two points representing binary opposites, a continuum is a line between those two points.

Take the above example.  If we say in response to that statement ‘no, we’re neither with you OR against you’, then a middle point is identified between the two extremes.  This creates a ‘continuum’: a line between two extremes.  A continuum can have an infinite number of possible points.

Continuum

As above. A continuum, technically, is an infinite series of points between two end points. In the context of argument it is a range of statements that express positions somewhere between two extremes.

By way of an example, the thesis ‘It’s good to be rich’ has, as mentioned, the anti-thesis ‘It’s bad to be rich.’  This might be the first that springs to mind.  But by looking at the terms in the original proposition, other ‘anti-theses’ can be found.  For example, it could be argued that the opposing argument is that ‘It’s good to be poor.’  Or that it’s WRONG to be rich, which is to define the opposite of good in a particular way.

Rhetorical fallacy

An archetypal mistake in argument.  A fallacious premise does not necessarily make an argument untrue. But the premise itself is not valid used as a support for a conclusion.

Rhetorical device

An archetypal device of content or style in rhetoric.